TL;DR : The latest version (16.0.14) of Operamini for iOS browser is affected by an Universal-XSS vulnerability which can be triggered by performing navigation from target domain to attacker controlled domain. When attacker controlled domain returns " javascript:code_here " in " location " header then browser executes the javascript code in the context of target domain instead of attacker domain. This vulnerability is yet not fixed by Opera team. Update [15 July 2019] : CVE-2019-13607 is assigned to this vulnerability. So while playing with Operamini browser I noticed that when a navigation to " javascript " protocol occurs via " location " header then browser executes the provided javascript code. For example if the value of " location " header is " javascript:alert() " then javascript code "alert()" gets executed by the browser. Normally browsers prevent navigation to " javascript: " URL...